Duplex telegraph system



April 17, 192s.

1,666,195 A. A. CLOKEY DUPLEX TELEGRAPH SYSTEM Filed May 13, 1927' by. y

6 /l avr/wey.

YParenteel Apr. i7, 1928.Y

fsrarf AILISON A. cLOKEYyOE RUTHERFORD, NEW JERsEaAssIGNO-n To BEL-'IilTEILEBONE LABORATORIES, IivcOIiieoIiAfrED,v or NEWYon-:regirI- Y, :ACORPORATION OFNVEW "YORK l 'Alipiicatin ined May 13,1927.'seriai'ivofiegsa yThis invention relatesto telegraphy and `moreparticularly to a duplex submarine Ytelegraph lcable system employingreceivii'ig apparatus'of tlie moving lcoil type.

An object of the invention is to prevent unbalancecurrents, 'due Vtotransmitted sigmain and the artificial line, from affecting* A ous othercondenser-s in the artiticiallineilthe Y ThisarrangementI`of adjustableresistances" nalimpulses'in a duplexv system in'wliicli there existsimperfect balance' between Vthe the receiving instrument associated withthe Y yduplex networkv at the sending station.

In duplex telegraph non-loaded submarine.

I cable systems, resistances are ordinarily inserted at the head. endsof the cable and artificial lin-e and at variousfotlier points alongtheartificial line7 land adjustable re- .sirstances are usuallyconnected in shunt with the linetlie armature is rot-atedby thelow yfrequency` imbalance current andV vtliuefc)n-r ta'ctsaremoved anequalamount in thejsame associated contacts is effected to` cause the'Vcondensers in the ratioarins and With vari-A -adj ustment of which willpermit of balai'ics ing theentire systemv quite' accurately for thehigher frequency components of vthe signal.

and con'densers doesv not, however, .permit lof i accurately balancingthe cable and tl'ievartificia] line for. very low frequencies Vwhich,may be caused by diiferences between the real and artificial -cables atgreat distances from the sending end: specific Y'object of tlie'presentinvention is lto kconiqieiisate in the receiving instrumentV forthiseifectof loW Y frequency imbalance currents Which cannot be removedby adjustment Vof the head end balancing resistances and condensers.

' Accordingto a specific embodiment of the present Ainvention theimbalance lcurrents of low frequencies are renderedineifectivebyproviding a relay which neutralizes unbalgance currents and thereby'limits the-opera-Y Vtion of a recording deviceto the received signalsonly. This relayis'ofthe polarized typeV and is equipped With tWoindependently rotatable coils khaving respectively afiixedv l thereto anarmature and a'pair of contacts,

the contacts being arranged in engageable l relationwith the armature.One coil is connected to the bridgeV across the yratiolarms marinetelegraph station.' ,f

ina bridge duplex systemand is responsive to Vboth received signalswand/the lovv ffreqiie'iicy imbalance currents o f transmitted signals,'and theother 4coil is connected y Vthrough vaf-suitable ynetwork to.the transmitterfand isA responsive only to currents similarin Wave formand'amplitude tothe low frequency unbalancencurrents liof trans,-A

mitted signals. rThe armature is connected directly to the recordingdevice and thereon-V tacts are connected to opposite `"teriiiina'lsVv ofa source'of currentusupply so thatWhen a f receive-d signal causes thearmature toje'ii- 'gage either Of'thefassociated contactslan operatingcircuit for the recording device lis closed. When a'signal istransmitted over.

direction byfa currentequivalent to tlieuii ment between the armature'and eitliferl'ofjfits operation of thefreco'rding device. 'Hofvvevery.`

should 'an incoming.signaljbe` receivedvvhile the armature and'contactsvare under-the con'- Vvtrol Aof a transmitted signahthe curreiityof theincoming signal, depending Aup'i'nrxifts polarity, would causeeitlierwan increasefor decrease'in the movement-of the,l armature f andtherebyeft'ect an engagemeiit'or 'disenl gagement WitlioneV oftheassociated contacts ,i

the incoming signal.

This iiiventionwill be 'in to operatetlie vrecording device andrecord"re particularly described in connectionwitli ythe,acfcompany-f bodimentof-tlie invention employedjat 'a terminal station rof* abridge ,duplexsub.

terminatingin a bridge` duplex lsetV in whichy Y ff an artificial `:line2`is provided for siniiilat'-r ing the impedance Aofthecable.r4 Inaccord ance with the vpresent.invention the system is assumed to be inperfectL balance for the Y high frequency' components of the signalingcurrents, vWhich'.k balance Vis obtained byad- Y' l justing resistances22 laiijdf,237jat the ^head f ends of the cableandftliefartificial'liiiegiref g spectively, resistances '24 'and25 .inthe rratio arms and the'impedancefelements?which are 1 'Y employed intheartificial lineQ. This ball# ance-however does iiot'holdffortheilovv fiquency components of the *signaling'fjcurrents. In this system therecording device -3 which may be any ofthe Well -knovvirtypes7 'y Y willrespond not only-.tothe incoming"sig- `nals but also' to the imbalancelow, frequency *Y In order .to'compensate for this unbalancci of *Ycomponents of the outgoing ,signal currents.

y nothe low frequency components of the transmitted'signalsand limit theoperation of recording device Sto the incoming signals only, relay 4f isprovided to control the operi ation of the-recordingdevice by.neutralizing vthe effects of the imbalance currents. This relay isequipped with two coils, namely, signal coil 5 and neutralizing coil' 6which are arranged when energized7 to rotate independently of each otherbetween the poles of their respectively associated magnets Z and 8.Thecoil 5 is responsive' to either the signals received from cable 1 orthe uubalance low frequency components oi the signals transmitted bytransmitter 9, and the coil 6 is damped so Vas to be responsive to onlythe low frequency components oir' the transmitted signals. in armature10 is fixedA tocoil 5 and contacts 11 and 12 are likewise ViiXed to coil6, that rotation ot veither coil alone etlects an engagement ordisengagement between the armature and one of the contacts,thereby'connecting'or disconnecting the operating circuit ot' recordingdevice 3 with battery 13. it is understood, of course, that theinvention is not to be limited to the Yembodiment shown, but

-that other types of relays may be employed,

such as one having fixed coils with two movable armatures one of whichcarries the lsingle contact and the other carries the pair ot ancecurrent in the circuit of coil. 5.

,In describing the operation oit the system, let vit be assumed thatincoming Vsignals are `beingreceived from cable 1. The signalspassthrough network '14, amplifier 15 and coil 5.y -Coil 5 rotates andmoves its armature to one side or the other depending upon the polarityof the incomingv signals, to connect one pole ot battery 13 to t-herecording device 3 which operates. toinake a record ot the incomingsignals. When a message is being transmitted from transmit-ter 9, thecurrent vof the outgoing signals divides at point 18, part going to theapex 19 and the other'part passing through `the circuit .of resistance16, network 17 and coil 6. AInasinuch as this invention is concerned'principally' inthe imbalance of the able nals, the cable and artificialline are regarded as being in nearly perfectV balance for the higherfrequency components of the signaling currents so that the higherfrequency components are ineffective vto operate either of the coils.

19 are balancedv outby the resistances 22, 23, 24, 25 and artificiallino 2 and thosetransmitted to coil 6 are rendered ineffective by inseries, thereby causing the armature 1()v to rotate to one side or theother, depending The higher fre-- quency components transmitted to the`apex se l upon the polarity of the outgoing signal.

Simultaneously with the tlow ot 'imbalance current through coil thecurrent'similar in wave orm'and oi' approximately the same amplitudecauses the contacts 11 and.

12 to `rotate vin a similar manner and inasmuch as these coils are soconnected that? thev contacts move in the same direction as thearmature, no relative movement between the armature and contacts resultsVfrom the imbalance current and no record is, theretore, made by therecording device. Y

Should signals be received during the v time that transmitter'Q issending amessage over cable 1, the current ot' the incoming signal wouldbe added in coily 5 to that olf the imbalance current -flowing thereinat the time, and if the currents happen to be of opposite polarities,the movement-,ot the armature 10 would be decreased and 'it ol the samepolarity the movement would be in'- creased, so that regardless ot whatthe polaritiesof the outgoing and incoming signals may be, a relativemotion vtakes place between the armature and the contacts to record thenature ot the incomingsigual.

The invention has been described above as applicable to ordinary duplextelegraph and non-loaded cable systems. However, it can also be employedwith loadedk lines and cables or elsewhere wherever the need exists formeans for accomplishing the function ot the invention.r y Y lWhat isclaimed is: Y

1. duplex system terminal arrangement comprising a main and anartificial line, a source oi current for transmitting signals, atranslating device responsive to incoming signals, and means forneutralizing disturbing e'ectsdue to importent lbalance between the mainand artiiicial lines, said means including independently movable membersarranged to move simultaneously in the same direction in response tooutgoing signals and i the imbalance currents producedthereby, .so :isto prevent relative movement `therebetween and the subsequent operationot-said translating device. i i* Q. Ina telegraphppsystem, a terminalduplex bridge arrangement comprising a main* and an artificial line, alcontact making device having operable contacts, a signaltr`anslatingidevice responsive to the operation A,of

said contacts, and separatel means for operating said contactssimultaneously to pre# I vent theoperation of saidgtranslating device inresponse to outgoing signals and to effect the operation f saidtranslating device by 1 the incomina signals lWhen' signals are being lv D i n simultaneously transmitted.

3. In a telegraph system, a 'duplex bridge arrangementcoinprising a mainandan artificial line, a contact making device comprising a plurality ofcoils each of which is arianged to be energized without vintei'fferingiiiagnetically'ivith the other, and movable y k,contacts on each of said'coils arrangedtov move in the same direction in respons'eto outgoing`signals and imbalance currents produced thereby, ,to prevent engagement1 between said. contacts, 1.

4. In a telegraph system, a duplexbridge arrangement comprising a mainand an arti`- iicial line inimperfect balance for the low frequencycomponents of the signaling cur-7 rents but in substantially perfectbalance 'for the higher frequency components, trans' initting means, asignal traiislating device, a

contact making device comprising a sigv` nal receiving coil and adisturbance neu'- tralizing coil, movable contacts iony 'peach i of saidcoilsV arranged when interengaged to operate said recording device, andmeans 'foi-.Y diverting a part ofthe transmittedV signal current throughvsaid dis,-

1 turbance neutralizing coil at thesame time Lior that the disturbingcurrent dueto the im' perfect balance is flowing through the sig-` nallreceiving'coil to move said contacts in Athe saine direction therebypreventing" the" interengagement of said contacts and the Voperation ofsaid translating device in response to low frequency imbalance currentsvresulting from the transmitted signals.

i 5. In a telegraph system, a .duplex bridge arrangement comprising amain and an artil fficia'l li'ne in imperfect balance forthe lowyfrequency components ofthe signaling currents but' in substantiallyperfect balance" for the higher frequency components, a

transmitting mechanism, a signal translating device, a contact makingdevice for conf p trolling said translating device, a signalreceivinfcoil on saidl contactin'akino device arrangedto be effectivelyenergized by both the received signalsxand the imbalance cui-- rents ofthe transmitted signals, contacts on said coil arrangedlto be operatedin either.

7 direction by said signals, thev direction depending upon the polarityof the signal, a

i disturbance neutralizingV coil-onv said contact making device arrangedto be effectively energized. by, only the loW frequency coniponents of.theoutgoing signaling currents, and contacts on said neutralizing coilv arranged to move in a direction `corresponding'Y to that ofthe'contact-s onsaid receivingcoil when thelatter coil is energizedv bythe unbalance currents only,` thereby preventingA linterengageinent ofsaid contacts and' neu-` tralizing the effect ofther imbalance currentsproduced in said receiving'coilL" Y 6. In a telegraph system, a duplexbridge' naling currents vand inVA substantially' perfect balance for thehigher' frequency ,composo; 1 i

nents, transmitting means, a signaltransr,A

lating device, a contactinaking device com#4 prising a signal receivingcoil-anda disturb ance. vneutralizing ycoil magnetically inde'- pendentlof eachother, movable contacts on ari"A each of saidv coils arrangedWhen interenjfw going signaling currents whereby' relative movement ofsaid' contacts if prevented,`

means for preventing the operationv of said coils in-response lto thehigher frequency components of the outgoing signalY currents, Y'

and means for energizing the receiving coil rgaged', to` operatesaidtranslating device',4 Y means for opeifatinglboth'lvcoils in responsetothe low` frequency components ofthe out- Vonly in response toincoming` signals Where-- by said contacts interengage to operatesaid ytranslating device.

f arrangement comprising a main-and an, arti 'iicial line'inimperfect*balancevkfor the low frequencycomponents of the outgoing sg-Llnaling currents and in substantiallyperfect balance for -fthe higher`frequency compo?4 v' nents, transmitting means, a' recordingde Ydevice, a contact making device comprising a signal receiving coil and.aiheavily damped disturbance neutralizing coil,"v movable con-V tactsonfeach of said coils arranged to interengageto operate said recordingdevice,

inea'nsfor operatingl both coils in response to the 10W' frequencycomponents of Vout- 't going signalv currents whereby relative movementVof said contacts is prevented, im-y pedance elements in the Aartificialline andY iicial' line for-cooperating With said damped InV a vtelegraphsystem, alduplexA bridge i j i175 'l Ithe head ends ofsaid cable landsaid', arti-' y` neutralizing coil* iii preventing the opera-,1r

tion of said contact making device in response" tothe higher frequencycomponents ofthe Y outgoing signaling currents, and .means forenergizing-the receiving coil only inre-` sponseto incoming signalswhereby said contacts interengage 'to operate said reco-rding device.

ii'iyinaine this l2 day of `May` A. D., 1927.v

`ALLisoiv kA. cLoKEY.

t 12: A In Witnessr` whereof, I hereunto subscribe I

